from typing import Optional

from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import jwt
from pydantic import ValidationError
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.config import settings
from app.core.security import ALGORITHM
from app.db.session import SessionLocal
from app.models.user import User
from app.schemas.token import TokenPayload

reusable_oauth2 = OAuth2PasswordBearer(
    tokenUrl=f"{settings.API_V1_STR}/auth/login/access-token"
)


async def get_db() -> AsyncSession:
    async with SessionLocal() as session:
        try:
            yield session
        except Exception:
            await session.rollback()
            raise


async def get_current_user(
    db: AsyncSession = Depends(get_db), token: str = Depends(reusable_oauth2)
) -> User:
    try:
        payload = jwt.decode(
            token, settings.SECRET_KEY, algorithms=[ALGORITHM]
        )
        token_data = TokenPayload(**payload)
    except (jwt.JWTError, ValidationError):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Could not validate credentials",
        )
    user = await db.get(User, token_data.sub)
    if not user:
        raise HTTPException(status_code=404, detail="User not found")
    return user


async def get_current_active_user(
    current_user: User = Depends(get_current_user),
) -> User:
    if not current_user.is_active:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


async def get_current_active_superuser(
    current_user: User = Depends(get_current_user),
) -> User:
    if not current_user.is_superuser:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="The user doesn't have enough privileges",
        )
    return current_user